Can I create a review coverage report targeting a single Mercurial/Git branch

I would like to see if all the commits made on a certain Mercurial/Git branch have a corresponding code review and if the reviews were all completed.

Is this possible? I see in the "Repositories" section there is a "Reports" that seems to show everything in the repository. And although I can select a branch in the "Commit Graph" tab. I don't see how to do that in the "Reports" tab.